The Asherman Chest Seal^™ (ACS ^™) Combat Pack is a safer approach to treating open pneumothorax and preventing tension pneumothorax in chest injuries from gunshot, stab wounds or other penetrating chest trauma. The unique one-way valve is designed to let air and blood escape while preventing re-entry of either, including four additional strips for added support. Proven to be a more effective treatment than standard petroleum gauze, the ACS^™ is standard issue for the U.S. Army, the British Army and the U.S. Navy.